Electric signaling device



atent fiice 3,921,520 Patented Feb. 13, 1962 3,021,520 ELECTRlCSIGNALDJG DE'VHCE Leo L. Weber, Logansport, End, assignor to Essex WireCorporation, Fort Wayne, Ind, a corporation of lindiana Filed Dec. 12,1%), Ser. No. 75,276 3 Claims. (Cl. 349-384} This invention relates toan electric signaling device comprising a combination sounder andvibrating reed relay. 1

Signaling devices of this type are intended for use in electricalsignaling systems employing a signal current of a predeterminedfrequency superimposed on power supply lines. In one such system whichhas been proposed for warning of an impending disaster, means areprovided for superimposing a 240-cyc1e signal on the 6,0-cycle powerlines. Frequency-responsive receivers connected to the power linesprovide an audible warning in response to a 240-cycle signal.

One form of receiver for such signaling systems employs an inductorconnected in series with a capacitor across the power lines in a circuitthat is resonant at the 240-cycle signal frequency. The inductor has anair gap in which a reed mechanically resonant at the 240-cycle frequencyvibrates when the signal current is applied to the power lines. Thevibrating reed closes a circuit to a timing device which energizes asounder if the 240-cycie signal is maintained for a predetermined periodof time. It has been proposed to also use the inductor to operate asounder clapper with 60-cycle power by shorting the series capacitor.Because the magnetization of the inductor is considerably greater whenenergized by the full power line voltage, the reed is subjected toexcessive and destructive forces.

It is, therefore, the object of this invention to provide an improvedcombination sounder and vibrating reed relay device of the foregoingtype in which the reed is protected from damage when the device isoperated as a sounder.

Another object is to provide an improved signaling device of theforegoing type which is relatively inexpensive to manufacture.

The signaling device in accordance with this invention comprises, inaddition to the inductor, the resonant reed and the clapper, an armatureassociated with the inductor which looks the reed in a fixed positionwhen the inductor is energized by the full voltage of the supply lines.The locking means of the armature are shaped to guide the reed to itslocked position despite the reeds having a large amplitude of vibrationwhen initially engaged by the armature.

Other objects and features of the invention will appear as the inventionis described in connection with the accompanying drawing in which:

FIG. 1 is a plan view of an electric signaling device embodying theinvention;

FIG. 2 is a side elevation of the signaling device;

FIG. 3 is a fragmentary sectional view taken along the line 3-3 of FIG.1; and

FIG. 4 is a schematic diagram of an electrical control of which thesignaling device may be an element.

Referring now to the drawing in detail, the numeral indicates asignaling device constructed in accordance with this invention. Thedevice 10 has a magnetic core 11 comprising a stack of laminations 12secured together by clamping members 13 and 14. The core 11 is ofgenerally H shape having a cross piece 16 and two legs 17 and 18terminating at one end in poles 19 and 20, respectively, and at theother end in perpendicularly disposed extensions 21 and 22,respectively, whose spaced ends define pole faces separated by an airgap 23. A that spring reed 24 of magnetic material supported by one endat 25 has its other end 26 disposed within the air gap 23. The reed 24may be polarized by a permanent magnet 27 and carries a contact 28 whichintermittently engages a relatively fixed contact 29 on bracket 30whenever the reed 24 vibrates with sufiicient amplitude. A clapper 31 ofresilient, magnetic material is positioned adjacent the poles 13 and 20and is free to vibrate when coil 32 on cross piece 16 of the core issuitably energized. The clapper 31 may carry a button 33 for strikingagainst a suitable sounding element (not shown), such as the side wallof an enclosure for the signaling device.

The leg 17 of core 11 carries a movable magnetic armature 34 whichoverlies the extensions 21 and 22. At one end the armature 34 has twonotches 35 disposed to accommodate bent-over projections 36 withsufficient clearance to permit movement of the free end of the armature34 relative to the core 11. A bent spring member 37 of non-magneticmaterial is secured at one end to armature 34 and has its other end inengagement with core leg 18 to normally bias the free end of armature 34away from the core 11. The armature 34 is formed with a notch 38 inlongitudinal alignment with the free end of the reed 24. The sides ofthe notch are defined by converging spaced lugs 39 bent approximately atan angle of 30 degrees from the plane of the armature 34 in a directionaway from the free end of the reed 24. When the armature 34 is attractedto the core 11, the inclined faces of the lugs 39 engage the free end ofreed 24 and guide it to a position where it fully enters the notch 38 asshown in FIG. 3.

The reed 24 is mechanically resonant at a selected frequency which, forexample, may be 240 cycles. When the coil 32 is energized by a signal ofthat frequency, the reed vibrates in core gap 23 and repeatedly closescontacts 28 and 29. The clapper 31 which may be a flexible, flat stripof magnetic material fixed at one end 40 and having its other end 41positioned adjacent the poles 19 and 20 of the core 11 is so constructedthat the required energizing power to vibrate it is considerably greaterthan that required to vibrate reed 24. In addition, the clapperpreferably should have a natural frequency of vibration lower than theoperating frequency of reed 24.

In FIG. 4, there is shown the control system of a receiver for asignaling system employing the signaling device of this invention. Thecoil 32 is connected in series with a capacitor 50 between conductors 51and 52 which, for purposes of illustration, may be assumed to be theusual -volt, 60-cyc1e household supply lines. The reactance value ofcapacitor 50 is selected so that the capacitor 50 and coil 32 are tunedto series resonance at the signal frequency. Thus, this circuit has ahigh impedance to the GO-cycle voltage and insufiicient 60-cycle currentflows through coil 32 to operate either reed 24 or clapper 31. Theheater 53 of an electric timing device 54 is also connected across theconductors 51, 52 and is energized whenever the reed 24 causes thecontacts 28, 29 to close. The timing device 54 includes a bimetal member55 responsive to heat developed by heater 53 to close contacts 56 and57. The contacts 56 and 57 are connected in a circuit-shunting capacitor50 and when they close the coil 32 is energized by the full line voltageof conductors 51, 52. A capacitor 58 may be connected across contacts28, 29 to minimize contact arcing.

When a continuous signal of predetermined frequency is superimposed onthe normal line voltage of conductors 51 and 52, reed 24 will vibrateand repeatedly close contacts 28 and 29. Closing of the contacts 28, 29energizes heater 53 and if the signal is maintained sufiiciently long,causes bimetal member 55 to close contacts 56, 57, thereby shortingcapacitor 50. With full line voltage applied to coil 32, the core is nowmagnetized at a much higher level. The clapper 31 will intercept someleakage flux between the poles 19, 20 of the core 11 and will vibrate ata rate corresponding to the flux pulsations which with a 60-cycle linevoltage will be 120 vibrations per second.

Because the magnetization of core 11 with full line voltage applied tocoil 32 is many times greater than that resulting from the relativelylow-voltage, high-frequency signal before the capacitor 59- is shorted,reed 24 would vibrate with a magnitude which could destroy it unlessfree motion of the reed is prevented. However, leakage flux from thecore extensions 2-1, 22 is effective upon energization of coil 32 by thefull line voltage to move the armature 34 toward the core 11 against theforce of spring member 37. As the armature 34 moves toward the core 11,the free end of the vibrating reed 24 is engaged by the inclined sidesof lugs 39 and guided into notch 38 where it is held. Contacts 28, 29 nolonger will close and after bimetal member 55 cools, capacitor 50 willbe reconnected in series with coil 32. This removes the full linevoltage from coil 32, and the clapper will discontinue its movement. Atthe same time spring member 37 moves armature 34 away from core 11 torelease the reed 24.

It will be apparent that signaling device of this invention may beemployed in receiver circuits other than that described above. It isalso apparent that various modifications may be made to the specificform of embodiment described herein without departing from the scope ofthe invention as set forth in the appended claims.

What is claimed is:

1. An electric signaling device comprising, in com bination: a vibratoryreed mounted to have a predetermined natural frequency of vibration; amagnetic clapper for producing an audible signal; an electromagnetdisposed adjacent said reed and said clapper for driving said reed andclapper; the clapper requiring an energizing power for its operationconsiderably in excess of the power required for driving said reed; amagnetic armature member disposed adjacent said electromagnet so as tobe attracted toward the electromagnet by flux therefrom whenever saidelectrornagnet is energized with power considerably in excess of thatrequired for driving said reed; said armature having latching meansengageable with said reed to limit the amplitude of vibration of saidreed whenever said armature is attracted toward said electromagnet; andmeans biasing said armature to a position in which said latching meansare disengaged from said reed.

2. An electric signaling device comprising, in combination: a magneticcore including two pairs of cooperating poles; an energizing coil forsaid core; a vibratory reed of magnetic material having a predetermined,natural frequency of vibration; said reed being mounted with a free endpositioned intermediate a first pair of said poles whereby energizationof said winding will drive said reed; normally open electric contactmeans associated with said reed and being alternately opened and closedupon vibration of said reed whereby said contact means may be closedwhen electrical energy at said predetermined frequency is applied tosaid coil; a magnetic clapper for producing an audible signal; saidclapper being mounted adjacent the second pair of said poles and beingvibrated in accordance with flux pulsations of said core when said coilis energized with power considerably in excess of that required fordriving said reed; a magnetic armature mounted adjacent said first pairof poles and movable from a normal position to an attracted positionwhenever said coil is energized with power considerably in excess ofthat required for driving said reed; said armature having a notch intowhich said free end of the reed moves when said armature moves to itsattracted position to limit the amplitude of vibration of said reedwhereby said electric contact means are held open; and spring meansbiasing said armature to said normal position.

3. An electric signaling device according to claim 2 wherein said coreis of a generally H shape with two legs and a cross piece; said coilbeing disposed on said cross piece; the adjacent ends of said legs atone end of the core defining said second pair of poles; said clappercomprising a resilient member fixed at one end and having its other endextending adjacent said second pair of poles so as to be attracted tosaid second pair of poles by alternating flux therefrom; the ends ofsaid legs at the other end of said core having perpendicularly disposedextensions with spaced end portions defining said first pair of poles;said armature being pivotally mounted on one of said extensions inoverlying relation to the air gap between said extensions; said notch insaid armature being formed by converging spaced lugs bent from the planeof the armature in a direction away from the free end of said reed.

No references cited.

